The Start of Winter: A Meteorological vs. Astronomical Debate
The start of winter is a topic of great interest, with calendars across the Northern Hemisphere stating that it will begin on December 21. However, for meteorologists, the start of the season happens three weeks earlier, on December 1. This discrepancy arises from the difference between meteorological seasons and astronomical seasons.
Meteorological Seasons: A More Practical Approach
Meteorologists and climatologists divide the year into four seasons based on temperature changes, rather than the Earth’s rotation. This approach is more practical for calculating statistics and comparing weather conditions to previous years. Under this system, the four seasons are each allotted three months, making it easier to track and predict weather patterns.
Astronomical Seasons: Based on Earth’s Rotation
The astronomical calendar, on the other hand, is based on the Earth’s orbit around the Sun and its tilt. This calendar marks the changing of the seasons with either a solstice or an equinox. The summer and winter solstices occur when the Northern Hemisphere is at its maximum tilt toward or away from the Sun, respectively. When the Earth’s axis isn’t tilted in favor of either direction, it’s referred to as an equinox, or the start of spring or fall.
The Start of Winter: A Debate
The start of winter depends on whether you’re referring to the astronomical or meteorological start. According to the meteorological season scheme, winter begins on December 1 and runs through February 28, which tends to be a better fit for the coldest time of the year than astronomical winter.
Weak La Niña Expected to Emerge and Last into Spring
The National Oceanic and Atmospheric Administration (NOAA) states that meteorological seasons were developed because of the ever-changing dates produced by the astronomical calendar. As a result, meteorologists will welcome the start of winter on December 1, rather than December 21.
Winter Outlook: La Niña Set to Emerge, Unleashing Large Swing Potential for More Snow, Frigid Temperatures
FARMERS ALMANACS ISSUE DUELING WINTER OUTLOOKS: ‘GENTLER’ OR ‘WHIRLWIND’?
Frequently Asked Questions
Q: What is the difference between meteorological seasons and astronomical seasons?
A: Meteorological seasons are based on temperature changes, while astronomical seasons are based on the Earth’s orbit around the Sun and its tilt.
Q: Why do meteorologists use a different start date for winter?
A: Meteorologists use a different start date because it’s more practical for calculating statistics and comparing weather conditions to previous years.
Q: What is the start date for winter according to the astronomical calendar?
A: The start date for winter according to the astronomical calendar is December 21.
Q: What is the start date for winter according to the meteorological calendar?
A: The start date for winter according to the meteorological calendar is December 1.
[Image: I-25 traffic between Speer Blvd. and 23rd Ave. exits in the snow in Denver, Colorado on Friday, November 8, 2024. (Photo by Hyoung Chang/The Denver Post)]
